1. Goodman and Gilman’s The Pharmacological Basis of Therapeutics;Gilman,2001
2. Indian Pharmacopoeia, Government of India, Ministry of Health and Family Welfare, The Indian Pharmacopoeial Commission, Ghaziabad, vol. 2, 2010, p. 164.
3. United State Pharmacopoeia 35/National Formulary 30, United State Pharmacopoial Convention Inc., Washington, DC, vol. 3, 2012, p. 4699.
4. British Pharmacopoeia, British Pharmacopoeial Commission, London, vol. 2, 2010, 2003, 2004.